ext4: Add flag to files with blocks intentionally past EOF

fallocate() may potentially instantiate blocks past EOF, depending
on the flags used when it is called.

e2fsck currently has a test for blocks past i_size, and it
sometimes trips up - noticeably on xfstests 013 which runs fsstress.

This patch from Jiayang does fix it up - it (along with
e2fsprogs updates and other patches recently from Aneesh) has
survived many fsstress runs in a row.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Jiaying Zhang 2010-02-24 09:52:53 -05:00 committed by Theodore Ts'o
parent 73b50c1c92
commit c8d46e41bc
4 changed files with 41 additions and 4 deletions

View File

@ -285,10 +285,11 @@ struct flex_groups {
#define EXT4_HUGE_FILE_FL 0x00040000 /* Set to each huge file */
#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
#define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */
#define EXT4_EOFBLOCKS_FL 0x00400000 /* Blocks allocated beyond EOF */
#define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */
#define EXT4_FL_USER_VISIBLE 0x000BDFFF /* User visible flags */
#define EXT4_FL_USER_MODIFIABLE 0x000B80FF /* User modifiable flags */
#define EXT4_FL_USER_VISIBLE 0x004BDFFF /* User visible flags */
#define EXT4_FL_USER_MODIFIABLE 0x004B80FF /* User modifiable flags */
/* Flags that should be inherited by new inodes from their parent. */
#define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\

View File

@ -3186,7 +3186,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
{
struct ext4_ext_path *path = NULL;
struct ext4_extent_header *eh;
struct ext4_extent newex, *ex;
struct ext4_extent newex, *ex, *last_ex;
ext4_fsblk_t newblock;
int err = 0, depth, ret, cache_type;
unsigned int allocated = 0;
@ -3367,6 +3367,19 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
EXT4_STATE_DIO_UNWRITTEN);
}
}
if (unlikely(EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL)) {
if (eh->eh_entries) {
last_ex = EXT_LAST_EXTENT(eh);
if (iblock + ar.len > le32_to_cpu(last_ex->ee_block)
+ ext4_ext_get_actual_len(last_ex))
EXT4_I(inode)->i_flags &= ~EXT4_EOFBLOCKS_FL;
} else {
WARN_ON(eh->eh_entries == 0);
ext4_error(inode->i_sb, __func__,
"inode#%lu, eh->eh_entries = 0!", inode->i_ino);
}
}
err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
if (err) {
/* free data blocks we just allocated */
@ -3500,6 +3513,13 @@ static void ext4_falloc_update_inode(struct inode *inode,
i_size_write(inode, new_size);
if (new_size > EXT4_I(inode)->i_disksize)
ext4_update_i_disksize(inode, new_size);
} else {
/*
* Mark that we allocate beyond EOF so the subsequent truncate
* can proceed even if the new size is the same as i_size.
*/
if (new_size > i_size_read(inode))
EXT4_I(inode)->i_flags |= EXT4_EOFBLOCKS_FL;
}
}

View File

@ -4456,6 +4456,8 @@ void ext4_truncate(struct inode *inode)
if (!ext4_can_truncate(inode))
return;
EXT4_I(inode)->i_flags &= ~EXT4_EOFBLOCKS_FL;
if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
@ -5305,7 +5307,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
}
if (S_ISREG(inode->i_mode) &&
attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
attr->ia_valid & ATTR_SIZE &&
(attr->ia_size < inode->i_size ||
(EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL))) {
handle_t *handle;
handle = ext4_journal_start(inode, 3);
@ -5336,6 +5340,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
goto err_out;
}
}
/* ext4_truncate will clear the flag */
if ((EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL))
ext4_truncate(inode);
}
rc = inode_setattr(inode, attr);

View File

@ -92,6 +92,15 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
flags &= ~EXT4_EXTENTS_FL;
}
if (flags & EXT4_EOFBLOCKS_FL) {
/* we don't support adding EOFBLOCKS flag */
if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
err = -EOPNOTSUPP;
goto flags_out;
}
} else if (oldflags & EXT4_EOFBLOCKS_FL)
ext4_truncate(inode);
handle = ext4_journal_start(inode, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);